Device for tapping stay-bolt holes



(No Model.) V

J. OONNELLY. DEVICE FOR TAPPING STAY BOLT HOLES.'

Patentedf Nov. 29, 1887 mimmsm'sz Wm WM N, PEYERS. Phoio-Lithugnpiur. Wnhingtnn. D. a

IlNITED STATES PATENT Gaston,

JAMES T. CONNELLY, OF HUNTINGTON, WEST VIRGINIA.

DEVICE FOR TAPPING STAY-BOLT HOLES.

SPECIFICATION forming part of Letters Patent No. 373,815, dated November 29, 1887.

Application filed August 18, 1887. Serial No. 247,280v (No model.)

To all whom it may concern.-

Be it known that 1, JAMES T. CoNNELLY, a citizen of the United States, residing at Hunt ington, in-the county of Oabell and State of West Virginia, have invented certain new and useful Improvements in Screw-Taps and Devices for Cutting Threads of StayBolt Holes in Fire-Boxes, Boilers, 800.; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to screw taps for threading stay-bolt holes of locomotive fireboxes. boilers, &c., where such stay-bolt holes v are behind the frame of the boiler or locomotive, without removing the frame or otherwise disturbing the engine.

Fireboxes of locomotives are generally made of an inner and an outer metal sheet or sheets, with a water-space between them, and are held in place and securely braced by numerous stay-bolts. The inside and outside shells of the firebox are subjected to great strain and wear, and thelstay-bolts are, consequently, frequently broken or become worn out and have to be replaced. Some of these stay-bolts are placed in the fire-box behind the frame or other portion of the boiler, and, here tofore, to replace one of these worn-out or broken bolts, it was necessary to remove the intervening frame from the outside of the en gine before a new bolt could be fitted in place. The removal of the frame must be executed by skilled workmen, and is a tedious and expensive operation and requires much time; and it is a well-known fact to those skilled in the art to which my invention appertains that when the frame or other part of the boiler or locomotive has been removed to replace a worn-out stay-bolt which is located behind said frame, and then replaced again, the replaced frame or part is never as strong as it was before being removed. L y

The object of my invention is to replace old stay-bolts with new ones Without removing the frame or otherwise disturbing any of the parts of the engine behind which said bolts are placed, and this end I accomplish by first removing the old bolt and then rethreading the stay-bolt hole-from the inside of the fire-box, and by then inserting a new stay-bolt from the inside of said box, which may thus be done quickly and effectively at comparativelylittle expense and without injury to the frame-work of the boiler.

The subject-matter claimed herein by me as of my invention is first described below, and is then particularly pointed out at the close of this specification.'

Theaccompanying drawings illustrate my improved apparatus, and in said drawings Figure 1 is a view in elevation of the tubular screw-tap used for threading the stay-bolt holes; and Fig. 2 is anend view thereof, looking at the rear, squared, or wrench end of the tap. Fig. 3 is aview of a spindle or rod having an enlargement or shoulder at one end for use with the tubular screw-tap. Fig. 4 is a View of another spindle or rod for use with said tap in replacing stay-bolts according to my improved method; and Fig. 5 is a sectional View of a. portion of a locomotive fire-box, showing the inner and outer shells of the firebox and illustrating my improved'tools in different stages of operation while threading staybolt holes, and also showing the relation the several parts of the device bear to each other. In carrying out my invention, I make use of a tubular screw-tap, A, the longitudinal bore a of which extends entirely through it, and this tubular tapis fitted to Work upon a spindle or rod, B, with an annular enlargement or shoulder, b, at one end, and upon a similar straight rod or spindle, 0, minus the enlargement or head of the rod B, in another step of the operation of threading the bolt-holes in the inner and outer shells of the fire-box. The tubular tap A is squared at one end, as at A, for the application of awrench, as usual. The fire-box is shown as consisting of the usual inner and outer shells, D and D, united at bottom by the usual bar, F, and it will be seen that some of the stay-bolts G thereof are placed behind the boiler frame-Work, (shown at E E5) and to replace a worn-out stay-bolt which is placed behind said frame the frame E has heretofore been removed.

To avoid removing the frame-work E of the engine or boiler when it is desired to replace an old stay-bolt, and attain the consequent saving of time, labor, expense, and injury to the engine, is the main'object of my invention, which may be practiced as follows: The workclear, as at d and d, Fig. 5.

man, from the inside of the fire-box, first extracts the old bolt from the hole into which it was first fitted and leaves the stay-bolt hole The spindle B is now passed from the inside of the fire-box through the hole din the inside sheet or shell, D, until the enlarged annular end I) of the spindle B rests in the hole (I of the outside sheet or shell, D, and against the frame-work E, which is opposite the hole 02, as shown in Fig. 5. The tubular sci ew-tap A is now fitted on the spindle B, said spindle 13 passing through the longitudinal bore a of said tap, and the tap A is turned by means of a wrench, as usual, placed on the squared end A, and cuts the, thread in the walls of the hole d. of the inside sheet or shell, D. It will thus be seen that as the enlarged end I) of the spindle B fits in the hole (1 of the outside sheet or shell, D, and the screw-tap A fits in the hole d of the inside sheet or-shell, D, the tap A is positively directed and guided in a right orstraight line relatively to the holes (I and d as it threads the walls of said hole (1, and is compelled to cut the thread of said hole in a right line with the holed in the outer shell, D. When the hole in the inner shell, D, is threaded, the spindle B, together with the tap A, is removed from the holes (I d, and the spindleG is inserted instead thereof, with the tap A fitted thereon as with the rod B, as shown also in Fig. 5. As the spindle Chas no enlargement on its outer end, which is placed in the hole (1 of the outer shell, D, the screw-tap A is allowed to cut its thread in the walls of said hole holes of both the inner and the outer shells of 5 the fire-box having thus been threaded without removing the frame-work E of the boiler or engine, or otherwise disturbing the engine, and exactly corresponding one with the other, constitute a perfcctly-th readed hole for the reception of the new stay-bolt, which can be inserted, in the ordinary manner, from the inside of the fire-box.

I claim as my invention- 1. The tubular screw-tap, substantially as described.

2. The combination of the tubular screw-tap having its bore extending its entire length with a guide-rod upon which it works, sub stantially as described.

3. The combination of the screw-tap having a longitudinal bore therein with the guide-rod or spindle having an enlargement at one end thereof, substantially as described.

In testimony whereofI affix my signature in presence of two witnesses.

JAMES T. CON NELLY.

\Vitnesses:

G. 13. SAMUELS, R. C. WARD. 

